Unique shot point navigation for Edgetech SB-424 chirp subbottom profiler data collected by the U.S. Geological Survey in Moultonborough Bay, Lake Winnipesaukee, New Hampshire in 2005 (Geographic, WGS 84, Esri point shapefile, 2005-004-FA_CHIRPSHT.SHP)

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Frequently anticipated questions:


What does this data set describe?

Title:
Unique shot point navigation for Edgetech SB-424 chirp subbottom profiler data collected by the U.S. Geological Survey in Moultonborough Bay, Lake Winnipesaukee, New Hampshire in 2005 (Geographic, WGS 84, Esri point shapefile, 2005-004-FA_CHIRPSHT.SHP)
Abstract:
In freshwater bodies of New Hampshire, the most problematic aquatic invasive plant species is Myriophyllum heterophyllum or variable leaf water-milfoil. Once established, variable leaf water-milfoil forms dense beds that can alter the limnologic characteristics of a waterbody, impacting natural lacustrine communities and their habitats. Variable leaf water-milfoil infestations also disrupt recreational uses of waterbodies and have negatively affected swimming, boating, fishing, and property values in and around several lakes and ponds in New Hampshire.
In 1965, Moultonborough Bay, Lake Winnipesaukee became the first waterbody in New Hampshire where variable leaf water-milfoil was observed. Variable leaf water-milfoil is native to the Southeastern and Midwestern areas of the United States where more alkaline waters appear to limit the growth of this plant. Outside its native range, however, it adapts well to the relatively acidic, low-alkalinity, and nutrient-poor conditions of oligotrophic lakes and bays similar to Moultonborough Bay.
In 2005, the New Hampshire Department of Environmental Services (NHDES) collaborated with the U.S. Geological Survey to investigate the distribution (presence and density) of variable leaf water-milfoil in Moultonborough Bay. This study utilized geophysical systems and conventional water-quality measurements to identify lake-floor environments that may provide suitable habitat for the establishment and growth of variable leaf water-milfoil. The results of the study are intended to assist resource managers in federal and state agencies by providing methods for detecting variable leaf water-milfoil and for identifying areas susceptible to infestation. Ultimately, this information may lead to early detection, prevention, and more effective mitigation strategies.
Field activity information for this cruise is available on-line through the U.S. Geological Survey Coastal and Marine Geoscience Data System https://cmgds.marine.usgs.gov/fan_info.php?fa=2005-004-FA.
  1. How might this data set be cited?
    U.S. Geological Survey, 2014, Unique shot point navigation for Edgetech SB-424 chirp subbottom profiler data collected by the U.S. Geological Survey in Moultonborough Bay, Lake Winnipesaukee, New Hampshire in 2005 (Geographic, WGS 84, Esri point shapefile, 2005-004-FA_CHIRPSHT.SHP): data release DOI:10.5066/F71N7Z4H, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts.

    Online Links:

    This is part of the following larger work.

    Denny, J.F., Danforth, W.W., Worley, C.R., and Irwin, B.J., 2014, High-resolution geophysical and sample data collected in Moultonborough Bay, Lake Winnipesaukee, New Hampshire in 2005, USGS Field Activity 2005-004-FA: data release DOI:10.5066/F71N7Z4H, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -71.390529
    East_Bounding_Coordinate: -71.361101
    North_Bounding_Coordinate: 43.728549
    South_Bounding_Coordinate: 43.710921
  3. What does it look like?
    https://cmgds.marine.usgs.gov/data/field-activity-data/2005-004-FA/data/seismics/2005-004-FA_chirpsht.jpg (JPEG)
    Image showing shot point navigation for chirp subbottom data collected by the U.S. Geological Survey in Moultonborough Bay, Lake Winnipesaukee, New Hampshire, 2005
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 26-Jul-2005Currentness_Reference: ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: vector digital data
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Vector data set. It contains the following vector data types (SDTS terminology):
      • Entity point (13773)
    2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000001. Longitudes are given to the nearest 0.000001. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257224.
  7. How does the data set describe geographic features?
    2005-004-FA_chirpsht
    Unique shot point navigation for chirp subbottom data collected by the U.S. Geological Survey during field activity 2005-004-FA in Moultonborough Bay, Lake Winnipesaukee, New Hampshire, 2005 (Source: U.S. Geological Survey)
    FID
    Internal feature number. (Source: Esri) Sequential unique whole numbers that are automatically generated.
    Shape
    Feature geometry. (Source: Esri) Coordinates defining the features.
    Line
    Line and file number for corresponding seismic files. This information is used during data acquisition, processing and archival. Format: L1F1, where L = Line; 1 = Line number; F= File; 1 = File number. (Source: U.S. Geological Survey) String up to 254 characters
    Shot
    Number of unique seismic shot (Source: U.S. Geological Survey)
    Range of values
    Minimum:1
    Maximum:6267
    Easting
    Easting coordinate in UTM Zone 19 meters, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:307453.5
    Maximum:309803.11
    Units:meters
    Resolution:0.01
    Northing
    Northing coordinate in UTM Zone 19 meters, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:4842479.28
    Maximum:4844492.44
    Units:meters
    Resolution:0.01
    Year
    Calendar year in which data were collected (USGS Field activity 2005-004-FA; 2005) (Source: U.S Geological Survey)
    ValueDefinition
    2005Calendar year in which data were collected.
    JD
    Julian Day during which sonar data were collected (2005) (Source: U.S. Geological Survey)
    ValueDefinition
    207Julian day is the integer number representing the interval of time in days since January 1 of the year of collection.
    HR
    Hour of Day (24 hour day). (Source: U.S. Geological Survey)
    Range of values
    Minimum:13
    Maximum:19
    Units:hour
    MIN
    Minute of the hour. (Source: U.S. Geological Survey)
    Range of values
    Minimum:0
    Maximum:59
    Units:minute
    SEC
    second of the minute. (Source: U.S. Geological Survey)
    Range of values
    Minimum:0
    Maximum:59
    Units:second
    Cruise
    Unique USGS field activity identification number in the format YYYY-NNN-FA where YYYY is the field activity year, NNN represents the number assigned to the field activity within that year, and FA stands for field activity. (Source: U.S. Geological Survey) String up to 50 characters
    System
    Chirp subbottom profiling system used to acquire seismic data during USGS field activity 2005-004-FA. (Source: U.S. Geological Survey) String up to 50 characters
    Acq_Date
    Date of data acquisition. Format MM/DD/YYYY. (Source: U.S. Geological Survey) String up to 50 characters

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    Jane F. Denny
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x 2311 (voice)
    508-457-2310 (FAX)
    jdenny@usgs.gov

Why was the data set created?

This shapefile contains shot point navigation for approximately 37 kilometers of chirp subbottom data collected with an Edgetech SB-424 chirp subbottom profiler by the U.S. Geological Survey during USGS survey 2005-04-FA. These data were collected in Moultonborough Bay, Lake Winnipesaukee, New Hampshire as part of a collaborative USGS and New Hampshire Department of Environmental Services research program to assess the distribution of variable leaf water-milfoil. The unique shot point navigation is generally used to aid in interpretation. The shot point navigation allows features in the seismic data to be correlated to features visible within the sidescan-sonar and bathymetry data.

How was the data set created?

  1. From what previous works were the data drawn?
    none (source 1 of 1)
    U.S. Geological Survey, Unpublished Material, Raw Chirp Subbottom Data.

    Type_of_Source_Media: online
    Source_Contribution:
    Chirp subbottom data were acquired with an Edgetech SB-424 chirp subbottom profiler. The SB-424 was deployed off the port side of the USGS R/V Rafael and towed close to the lake surface. Approximately 37 km of chirp subbottom data were collected.
    Data were recorded at a 75-millisecond (ms) record length (1875 samples, 40 microsecond sample interval) and a 4-24 kHz sweep and were logged using Triton-Elics Delph seismic acquisition software (version 2005) in Society of Exploration Geophysicists Y (SEG-Y) format (Barry and others, 1975) with WAAS navigation logged to the SEG-Y file trace headers. Navigation in the SEGY header was stored as seconds of arc. The raw chirp SEGY contained 3 channels: raw, match-filtered, and envelope detected. The envelope detected channel was used for data processing.
  2. How were the data generated, processed, and modified?
    Date: 2013 (process 1 of 3)
    A C-shell script was executed using Sioseis (v. 2011.2.7) to read the raw SEG-Y file and write out a new SEG-Y file with the shots renumbered starting at 1. A second C-shell script was executed using Seismic Unix (version 4.1) to read the renumbered SEG-Y files, write a Seismic Unix format file (*.su), and extract SEG-Y trace header information, which included shot number, source x (arc seconds), source y (arc seconds), year, Julian Day, hour, minute, second (UTC). Geographic coordinates (stored in arc seconds WGS 84) were converted to eastings and northings, UTM, Zone 19N, meters using proj (v. 4.7.1). Before saving the header information to a text file, the data were filtered using AWK (no version) to save only unique shot point locations. The unique shot navigation for each seismic line were then concatenated into a comma delimited (.csv) text file. The header records for the first several shots contained no navigation information, therefore the 'first' shot of the line is considered the first shot with usable data stored in the header. This was generally within the first 10 shots for the majority of lines. (Stockwell, 2005)
    Jane F. Denny performed this and all subsequent process steps. Person who carried out this activity:
    Jane F. Denny
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x2311 (voice)
    508-457-2310 (FAX)
    jdenny@usgs.gov
    Date: 2013 (process 2 of 3)
    The text file (*.csv) was imported into Esri ArcMap 9.3 using ArcCatalog, Create Feature Class from XY Table, specifying UTM, Zone 19N, WGS84 coordinate system. The point shapefile was then reprojected to Geographic Coordinate System, WGS 84 (GCS_WGS_1984). The point shapefile was visually inspected for spurious data points.
    The following fields were added to the point shapefile table: Cruise, System, and Acq_Date.
    Date: 06-Apr-2017 (process 3 of 3)
    The online links to the data were updated to reflect the new server hosting the data. Additionally, other small edits could be made to the metadata, such as modifying http to https where appropriate. The metadata date (but not the metadata creator) was edited to reflect the date of these changes. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
  3. What similar or related data should the user be aware of?
    Argue, Denise M., Kiah, Richard G., Denny, Jane F., Deacon, Jeffrey R., Danforth, William W., Johnston, Craig M., and Smagula, Amy P., 2007, Relation of Lake-Floor Characteristics to the Distribution of Variable Leaf Water-Milfoil in Moultonborough Bay, Lake Winnipesaukee, New Hampshire, 2005: Scientific Investigations Report 2007-5125, U.S. Geological Survey, Reston, Virginia.

    Online Links:

    Stockwell, John, 2005, Seismic Un*x: Center for Wave Phenomena - Colorado School of Mines, Golden, Colorado, USA.

    Online Links:

    Barry, K.M., Cavers, D.A., and Kneale, C.W., 1975, Report on recommended standards for digital tape formats: Geophysics v. 40, no. 02, p. 344-352., Society of Exploration Geophysicists (SEG), Houston, Texas.

    Online Links:


How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
    All attributes were evaluated during processing as standard quality control to ensure attributes contain accurate and relevant information and values.
  2. How accurate are the geographic locations?
    Navigation was acquired with Wide Area Augmentation System (WAAS), which is accurate to + or - 1 to 2 meters, horizontally. Navigation data were acquired with a LGBX Pro receiver and sent to Triton-Elics Delph seismic acquisition software, where Chirp sub-bottom data were recorded in Society of Exploration Geophysicists Y (SEG-Y) format (Barry and others, 1975) with DGPS logged to the SEG-Y trace headers.
    The Edgetech SB-424 chirp subbottom profiler was towed near the surface, close to the R/V Rafael. The instrument was secured in this position throughout the survey. Due to this tow configuration, any layback was minimal. The overall horizontal accuracy, given even a small (~ 1 meter) offset between the WAAS antenna and the tow-body, is + or - 5 meters.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    This shapefile contains unique shot point navigation for lines 43 -81, 84 - 112 of chirp subbottom data collected on JD 207(07/26/2005) during USGS field activity 2005-004-FA. Lines 43 - 81, 84 - 112 were a 'rerun' of lines 1 - 42 to try to improve on the data quality as there were significant system errors and malfunctions during data collection on JD 206 (07/25/2005). Shot point navigation for lines 1 - 42 are not included in this dataset. They were not used for interpretative purposes.
  5. How consistent are the relationships among the observations, including topology?
    All subbottom data were collected during USGS cruise 2005-004-FA using an Edgetech SB-424 chirp subbottom profiler. Seismic trackline navigation was generated from unique shot navigation for the seismic system. The unique shot navigation data were evaluated during processing for spurious points; all spurious points were removed prior to generating the trackline navigation.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints: None.
Use_Constraints:
Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of the dataset.
  1. Who distributes the data set? (Distributor 1 of 1)
    Jane F. Denny
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x2311 (voice)
    508-457-2310 (FAX)
    jdenny@usgs.gov
  2. What's the catalog number I need to order this data set? The file 2005-004-FA_chirpsht.zip contains the shapefile 2005-004-FA_chirpsht.shp and other files associated with the shapefile. In addition to the shapefile, the zip file also contains the data in CSV format (2005-004-FA_chirpsht.csv), the browse graphic (2005-004-FA_chirpsht.jpg) and the FGDC CSDGM metadata in the following formats: XML, HTML, FAQ and text.
  3. What legal disclaimers am I supposed to read?
    Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
  4. How can I download or order the data?
  5. What hardware or software do I need in order to use the data set?
    This zip file contains data available in Esri shapefile format. The zip file also contains associated metadata. The user must have ArcGIS or ArcView 3.0 or greater software to read and process the data file. In lieu of ArcView or ArcGIS, the user may utilize another GIS application package capable of importing the data. A free data viewer, ArcGIS Explorer, capable of displaying the data is available from Esri at www.esri.com.

Who wrote the metadata?

Dates:
Last modified: 06-Apr-2017
Metadata author:
Jane F. Denny
U.S. Geological Survey
Geologist
384 Woods Hole Road
Woods Hole, Massachusetts
USA

508-548-8700 x2311 (voice)
508-457-2310 (FAX)
jdenny@usgs.gov
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

Generated by mp version 2.9.36 on Thu Apr 06 15:50:28 2017